Alternate: Thinking 'Outside the Box' to Implement Advanced Biosolids Technologies

Solids handling has become an increasingly important aspect of the wastewater recovery industry as we deal with new pressures on hauling costs, limitations on historical outlets, drivers for improved energy recovery, and emerging regulatory pressures. The industry is being asked to reduce the total mass of biosolids products while also considering implementation of high temperature and/or pressure processes to comply with potential regulations of emerging contaminants. These new processes require additional handling within the facility. This presentation will focus on the elements of solids handling 'outside the box' to incorporate a wide range of advanced solids technologies including thermal hydrolysis, thermal drying, pyrolysis, gasification and supercritical water oxidation. The conversation around each element will include how it relates to upstream and downstream processes, the impact on O&M efforts and some practical implementation considerations for each. Elements that will be discussed include solids screens, low pressure cake conveyance, high(er) pressure cake pumping, high temperature elements, and final product management. A primary challenge facing WRRFs in the implementation of advanced solids treatment is how to best incorporate these processes into their existing plant and also ensure that the solids feed to these processes meet the often-specific requirements of these treatment approaches. The primary elements and impacts that will be discussed are: 1. Solids Screens -- how does the removal of stringy or fibrous materials either benefit or negatively impact dewatering, drying or processes with reduced flow path areas. 2. Low Pressure Cake Conveyance -- how can WRRFs best balance containment, agitation, energy consumption, cake consistency and downstream process integration while ensuring a consistent and reliable solids feed to advanced solids treatment processes. 3. High(er) Pressure Cake Pumping -- how can higher pressure feed requirements be safely and reliably implemented through intentional design incorporating online monitoring and passive safety features, operational controls, and standard operating procedures that ensure long term performance. 4. High Temperature Elements -- how can WRRFs maintain safe and reliable operation with systems that require skills sets that are vastly different than those traditionally required in the wastewater industry while achieving energy efficiency and operational high performance. 5. Final Product Management -- how can realistic reliability be achieved while transporting and handling solids with increasingly abrasive properties while also ensuring safe atmospheres, high levels of pipe integrity and consistency in transport to final beneficial use destinations. As the wastewater recovery industry moves into the future, a detailed understanding of how to integrate these elements into the existing treatment process is critical to long-term success. At the heart of the discussion is how to best 'manage the interfaces' to bring the whole facility together. This requires careful consideration during the design phase as well as careful thinking during implementation to ensure that operations and maintenance staff are educated on these new elements and are equipped with the tools needed to effectively use these new facilities to achieve new goals.